Tuesday, February 4, 2014

Reading List: Safe Is Not an Option

On August 24th, 2011 the third stage of the Soyuz-U rocket
carrying the
Progress M-12M
cargo craft to the
International
Space Station (ISS) failed during its burn, causing the craft and
booster to fall to Earth in Russia. While the crew of six on board
the ISS had no urgent need of the supplies on board the Progress,
the booster which had failed launching it was essentially identical
to that which launched crews to the station in Soyuz spacecraft.
Until the cause of the failure was determined and corrected, the
launch of the next crew of three, planned for a few weeks later,
would have to be delayed. With the Space Shuttle having been retired
after its last mission in July 2011, the Soyuz was the only way for
crews to reach or return from the ISS. Difficult decisions had to be
made, since Soyuz spacecraft in orbit are wasting assets.

The Soyuz has a guaranteed life on orbit of seven months. Regular crew
rotations ensure the returning crew does not exceed this
“use before” date. But with the launch of new Soyuz
missions delayed, it was possible that three crew members would have
to return in October before their replacements could arrive in a
new Soyuz, and that the remaining three would be forced to leave
as well before their craft expired in January. An extended delay
while the Soyuz booster problem was resolved would force ISS managers to choose
between leaving a skeleton crew of three on board without a known
to be safe lifeboat or abandoning the ISS, running the risk that
the station, which requires extensive ongoing maintenance by the crew
and had a total investment through 2010 estimated at US$ 150 billion
might be lost. This was seriously considered.

Just how crazy are these people? The
Amundsen-Scott
Station at the South Pole has an over-winter crew of around 45
people and there is no lifeboat attached which will enable them, in
case of disaster, to be evacuated. In case of fire (considered the
greatest risk), the likelihood of mounting rescue missions for the
entire crew in mid-winter is remote. And yet the station continues
to operate, people volunteer to over-winter there, and nobody thinks
too much about the risk they take. What is going on here?

It appears that due to a combination of Cold War elevation of astronauts
to symbolic figures and the national trauma of disasters such as
Apollo I, Challenger, and Columbia,
we have come to view these civil servants as
“national treasures”
(Jerry Pournelle's
words from 1992) and not volunteers who do a risky job on a par with
test pilots, naval aviators, firemen, and loggers. This, in turn,
leads to statements, oft repeated, that “safety is our
highest priority”. Well, if that is the case, why fly?
Certainly we would lose fewer astronauts if we confined their
activities to “public outreach” as opposed to the
more dangerous activities in which less exalted personnel engage
such as night aircraft carrier landings in pitching deck conditions
done simply to maintain proficiency.

The author argues that we are unwilling to risk the lives of
astronauts because of a perception that what they are doing,
post-Apollo, is not considered important, and it is hard to
dispute that assertion. Going around and around in low Earth
orbit and constructing a space station whose crew spend most
of their time simply keeping it working are hardly
inspiring endeavours. We have lost four decades in which the
human presence could have expanded into the solar system,
provided cheap and abundant solar power from space to the Earth,
and made our species multi-planetary. Because these priorities
were not deemed important, the government space program's mission
was creating jobs in the districts of those politicians who
funded it, and it achieved that.

After reviewing the cost in human life of the development of
various means of transportation and exploring our planet, the author
argues that we need to be realistic about the risks assumed by
those who undertake the task of moving our species off-planet
and acknowledge that some of them will not come back, as has
been the case in every expansion of the biosphere since the first
creature ventured for a brief mission from its home in the sea
onto the hostile land. This is not to say that we should design
our vehicles and missions to kill their passengers: as we move
increasingly from coercively funded government programs to
commercial ventures the maxim (too obvious to figure in the
Ferengi
Rules of Acquisition)
“Killing customers is bad for business” comes increasingly
into force.

Our focus on “safety first” can lead to perverse choices.
Suppose we have a launch system which we estimate that in one
in a thousand launches will fail in a way that kills its crew.
We equip it with a launch escape system which we estimate that
in 90% of the failures will save the crew. So, have we reduced
the probability of a loss of crew accident to one in ten thousand?
Well, not so fast. What about the possibility that the crew escape
mechanism will malfunction and kill the crew on a mission
which would have been successful had it not been present? What if
solid rockets in the crew escape system accidentally
fire in the vehicle assembly building killing dozens of workers
and destroying costly and difficult to replace infrastructure?
Doing a total risk assessment of such matters is difficult and
one gets the sense that little of this is, or will, be done
while “safety is our highest priority” remains the
mantra.

There is a survey of current NASA projects, including the grotesque
“Space
Launch System”, a
jobs
program targeted to the
constiuencies of the politicians that mandated it, which has no
identified payloads and will be so expensive that it can fly so
infrequently the standing army required to maintain it will
have little to do between its flights every few years and lose the
skills required to operate it safely. Commercial space ventures
are surveyed, with a candid analysis of their risks and why
the heavy hand of government should allow those willing to accept
them to assume them, while protecting the general public from
damages from accidents.

The book is superbly produced, with only one typographic error I noted
(one “augers” into the ground, nor “augurs”)
and one awkward wording about the risks of a commercial space
vehicle which will be corrected in subsequent editions. There is a
list of acronyms and a comprehensive index.

Disclosure: I contributed to the Kickstarter project which funded the
publication of this book, and I received a signed copy of it as a
reward. I have no financial interest in sales of this book.